The effects of calcination temperature and nickel/cobalt ratios on the formation of structure were also investigated. XRD results show that all samples which were calcined from 6000C to higher temperature for 1 hour were in single cubic spinel phases. The magnetic properties include saturation magnetization (Ms) and coercivity (Hc) have been also investigated by using vibrating sample magnetometer (VSM). | SCIENCE & TECHNOLOGY DEVELOPMENT, Vol 19, 2016 Synthesis of nano Co1-xNixFe2O4 by sol-gel method and its properties Nguyen Truong Xuan Minh Pham Le Kieu Oanh Huynh Ky Phuong Ha Le Minh Vien Ho Chi Minh city University of Technology, VNU-HCM. (Manuscript Received on July, 2016, Manuscript Revised on September, 2016) ABSTRACT Nano ferrites have received considerable cubic spinel phases. The magnetic properties attentions due to their various applications such as magnetic or catalyst materials. In this work, include saturation magnetization (Ms) and coercivity (Hc) have been also investigated by nickel-cobalt ferrite (Co1-xNixFe2O4) was synthesized by sol-gel method using stearic acid. using vibrating sample magnetometer (VSM). The saturation magnetization and coercivity of The effects of calcination temperature and nickel/cobalt ratios on the formation of structure CoFe2O4 calcined at 6000C for 1hour is emu/g and Oe, respectively. The were also investigated. XRD results show that saturation magnetization and coercivety of all samples which were calcined from 6000C to higher temperature for 1 hour were in single substituted materials decrease with increasing Ni content. Keywords: Nano Co1-xNixFe2O4, magnetic materials, sol-gel method. 1. INTRODUCTION Ferrite compounds are magnetic materials which are used in many technological applications because of their good combination of magnetic and electrical properties. The spinel ferrite (MFe2O4, where M are Zn, Mn, Ni, and Co) is a kind of material system for highfrequency passive components because of its high permeability, resistivity and permittivity [1-3]. Among magnetic nano powders, Co1-xNixFe2O4 nano powders are a class of Trang 122 magnetic material with excellent performance, prominently chemical stability, resistance to oxidation, moderate saturation magnetization, high mechanical strength [4-6], inverse spinel structure, a well-known hard magnetic .
